1. Technical Field of the Invention
This invention relates to a disk cartridge containing a disk-shaped recording medium such as an optical disk or a magneto-optical disk.
2. Related Background Art
Disk cartridges containing a disk-shaped recording medium such as a magneto-optical disk are known.
Referring to FIG. 1 of the accompanying drawings, disk cartridge 101 of the type under consideration comprises a cartridge main body 106 having an upper shell 111 and a lower shell 112, which upper and lower shells 111, 112 are typically made of a resin material. The cartridge main body 106 is provided with substantially rectangular openings 115, 115 that are arranged oppositely and across the inner and outer peripheries of the magneto-optical disk 105 so as to expose part of the recording area of the magneto-optical disk 105 to the outside for the purpose of signal recording/reproduction.
The cartridge main body 106 is additionally provided at the bottom side thereof with another opening 117 for allowing the disk table of the disk drive mechanism (not shown) for driving and rotating the magneto-optical disk 105 to move into the cartridge main body 106, said opening 117 for driving the magneto-optical disk (to be referred to as drive opening 117 hereinafter) being located adjacent to the bottom side opening 115 for recording/reproduction (to be referred to as recording/reproduction opening 115 hereinafter) with a frame section (not shown) arranged between them.
Referring also to FIG. 1, the cartridge main body 106 is provided with a movable shutter member 120 adapted to openably close the recording/reproduction openings 115, 115 and the drive opening 117. Referring now to FIG. 2 of the accompanying drawings, the shutter member 120 comprises an upper shutter section 121 for openably closing the recording/reproduction opening 115 of the upper shell 111, a lower shutter section 122 for openably closing the recording/reproduction opening 115 of the lower shell 112 and a link section 123 coupling the upper shutter section 121 and the lower shutter section 122 at an edge thereof. The lower shutter section 122 of the shutter member 120 is movably supported at the free end thereof by a guide section arranged on the main surface of the lower shell 112.
As the disk cartridge 101 having the above described configuration is mounted on a corresponding recording/reproduction apparatus, the shutter member 120 is moved to expose the recording/reproduction openings 115, 115 and the drive opening 117 by the shutter opening/closing member of the recording/reproduction apparatus. Then, the disk table of the disk drive mechanism (not shown) of the recording/reproduction apparatus is made to move into the disk cartridge 101 through the drive opening 117 in order to drive the magneto-optical disk 105 to rotate, while the recording/reproduction means of the recording/reproduction apparatus is made to move into the disk cartridge 101 through the recording/reproduction openings 115, 115 in order to record information onto or reproduce information from the magneto-optical disk 105.
In recent years, as a result of the remarkable increase in the amount of information to be handled on a magneto-optical disk cartridge, there is a large demand for magneto-optical disks having a large recording capacity. To meet the demand, efforts have been made to raise the recording density of the recording area of the recording medium and, at the same time, extend the recording area toward the outer and inner peripheries thereof. As an attempt for extending the recording area, there have been proposed disk cartridges 101 wherein the lower recording/reproduction opening and the drive opening are not separated from but held in continuation to each other in order to allow the recording/reproduction means of the recording/reproduction apparatus to move inwardly beyond the inner boundary of the recording area of the magneto-optical disk.
However, such disk cartridges have the following drawbacks. Firstly, since the disk cartridge 101 has the lower recording/reproduction opening 115 and the drive opening 117 in continuation to each other and the lower shell 112 of the cartridge main body 106 does not have a frame section located at the middle of the lower shutter section 122 for openably closing the lower recording/reproduction opening 115 and the drive opening 117 in order to separate the openings 115, 117 and hold them in position, the relatively elongated recording/reproduction openings 117, 117 can easily become deformed.
Secondly, since the lower shell of the cartridge main body is normally prepared by injection molding a thermoplastic synthetic resin material, the bottom surface of the cartridge main body can be warped downwardly or upwardly as shown in FIG. 3A or FIG. 3B, whichever appropriate.
As a result of the warp of the lower shutter section 122 and the deformation of the lower shell caused by the molding process, a gap can arise between the lower shutter section and the lower shell if the lower shutter section is at the position for closing the lower recording/reproduction opening and the drive opening to allow dirt particles to enter the cartridge main body.
In the case of a disk cartridge containing a magneto-optical disk adapted to high density recording, the dirt particles that have entered the cartridge main body can adhere to the recording area of the magneto-optical disk or move further into the recording/reproduction apparatus to hinder the normal recording/reproduction process on the magneto-optical disk.
In view of the above identified problems and other problems, it is therefore the object of the present invention to provide a disk cartridge that can effectively prevent dirt particles from entering the cartridge main body and improve the reliability of the operation of signal recording/reproduction on the disk-shaped recording medium.
According to the invention, the above object is achieved by providing a disk cartridge comprising:
a disk-shaped recording medium;
a cartridge main body containing said disk-shaped recording medium;
recording/reproduction openings formed in said cartridge main body to partly expose said disk-shaped recording medium to the outside across the inner and outer peripheries thereof;
a drive opening adapted to allow the disk drive means for driving and rotating said disk-shaped recording medium to move into said cartridge main body;
a shutter member having shutter sections and arranged outside said cartridge main body to openably close said recording/reproduction openings and said drive opening; and
a shutter cover arranged at least on one of the main surfaces of said cartridge main body to cover the moving areas of said shutter sections and having an opening slightly smaller than either of the shutter sections of said shutter member, said opening being arranged at a position corresponding to said recording/reproduction openings and said drive opening.
With a disk cartridge according to the invention and having a configuration as described above, the moving areas of the shutter sections of the shutter member are covered by the shutter cover so that any possible warp of the shutter sections along the main surfaces is suppressed by the shutter cover and dirt particles are prevented from entering the cartridge main body through the gap between the outer peripheral areas of the shutter sections and the cartridge main body when the recording/reproduction openings and the drive opening are closed by the shutter sections. When the shutter members are removed from the recording/reproduction openings and the drive opening to expose the openings, the recording/reproduction means of the recording/reproduction apparatus can enter the cartridge main body through the opening of the shutter cover.
Thus, with a disk cartridge having a shutter cover according to the invention, dirt particles are prevented from entering the cartridge main body through the gap between the outer peripheral areas of the shutter sections and the cartridge main body when the recording/reproduction openings and the drive opening are closed by the shutter sections so that the operation of recording information on or reproducing information from the disk-shaped recording medium can be conducted with an enhanced reliability.